<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Document</title>
    <style>
        * {
            margin: 0;
            padding: 0;
        }
        .container {
            width: 800px;
            height: 200px;
            font-size: 0px;
        }
        .left {
            background-color: red;
            display: inline-block;
            width: 200px;
            height: 200px;
            font-size: 14px;
        }
        .right {
            background-color: blue;
            display: inline-block;
            width: 600px;
            height: 200px;
            font-size: 14px;
        }
    </style>
</head>
<body>
    <div class="container">
        <div class="left">
            left
        </div><div class="right">
            right
        </div>
    </div>
</body>
</html>